Electrically driven fan



4 Sheets-Sheet 1 Filed June 25, 1945 y 6, 1954 K. J. WAHLBORG 2,682,826

' ELECTRICAL-LY DRIVEN FAN Filed June 25, 1945 4 Sheets-Sheet 2 a J 6:?a

w 29 W //M i k 52% WQW July 6, 1 4 K. J. WAHLBORG ELECTRICALLY DRIVENFAN 4 Sheets-Sheet 4 Filed June 25, 1945 hl INVEN 0 BY? Patented July 6,1954 7 2,682,826 ELECTRICALLY DRIVEN FAN Karl John Wahlborg, Stockholm,Sweden, as-

signor, by mesne assignments, toAktiebolaget B. A. Hjorth & 00.,Stockholm, Sweden, a corporation of Sweden Application June 25, 1945,Serial No. 601,444

Claims priority, application Sweden July 12, 1944 8 Claims.

This invention relates to a ventilator unit of a type which is employedto circulate air through a duct or opening in a building wall of anenclosure.

The object of this invention is to provide an improved ventilator unitof this type which can be conveniently employed to circulate air throughan existing duct in a building wall, the construction being such thatthe unit occupies a minimum amount of space at the inner face of thewall and a part thereof telescopically fits into the duct itself.

According to the present invention, the ventilator unit embodies abox-like casing having a rear wall adapted to be mounted on the buildingwall or the like so as to cover the existing air duct and an airpassageway extending therethrough, and amotor-fan' unit carried by thecasing, the fan being'disposed-in the air passagethe box-like casing ismounted at or'immediate ly adjacent to the inner surface of the buildingwall. With such an arrangement it is very easy to mount the ventilatorunit on a wall of an existing air duct even when the size'of the ductdoes not correspond with the diameter of the passageway in which thefan: 'is positioned, and also when the duct may be rectangular in shapewith its greater dimension in a vertical direction. By providing aventilator unit having a box-like casing the rear wall thereof may beapplied to ducts which vary considerably in size. Since the rearwardlyextending motor telescopically fits into the duct, the casing whenmounted on a building wall will project from the inner surface thereofinto the enclosure a distance which is less than the overall axialdistance taken up by the fan and motor, thereby providing a neat andcompact-ventilator unit which is essentially disposed in its entiretywithin the enclosure and readily removable for inspection and cleaning.

The invention, together with the above and otherobjects and advantagesthereof, will be described more fully hereinafter in connection with theaccompanying drawings forming a part of this specification, and inwhich:

Fig. 1 is a side'view, partly in section, of a ventilator unit embodyingthe invention;

Fig. 2 is a side elevation of the ventilator unit shown in Fig. 1;

Fig. 3 is a front view, partly broken away and in section, of theventilator unit shown in Figs. 1 and 2, the damper being omitted toillustrate details more clearly;

Fig. 4 is a wiring diagram for the ventilator unit shown in Figs. 1 to3;

Fig. 10 is a front elevation of the damper'and. switch operatingmechanism shown in Figs. 1.

and 3, the front member of the casing being .omitted to show detailsmore clearly;

Fig. 11 is a top plan view of the operating mechanism illustrated inFig. 10;

Fig. 12 is a side elevation of the operating mechanism shown in Figs. 10and 11;

Figs. 13, 15 and 17 are fragmentary vertical views of the damper andswitch operating mechanism, being similar to the details of suchmechanism shown in Fig. 6 and illustrating'the different operatingpositions thereof;

Figs. 14, 16 and 18 are horizontal sectional views similar to Fig. 7which correspond to the operating positions of the damper and switchoperating mechanism illustrated in Figs. l3, l5 and 17, respectively,Fig. 14 being taken at line l4--l4 of Fig. 13, Fig. 16 at line iii-l6 ofFig. 15, and Fig. 18 on line l8l8 of Fig. 1'7; and

Fig. 19 is a transverse sectional view of the operating mechanismillustrated in Fig. 15.

Referring to Figs. 1 to 3, l0 designates gen erally a box-shaped outerfan casing, preferably made of sheet metal, which is arranged to carry arectangular-shaped shutter or damper H, and H denotes the wall of acylindrical fan wheel drum defining an air passageway in which a fan I4is disposed. The fan I4 is driven by a motor 4 .5; it which isresiliently suspended. The suspension device in the embodiments showncomprises three S-shaped clips I5, preferably made of spring steel,having their outer arms either, as in the embodiment shown in Figs. 1 to3, extending through the rear wall 21 of the box-like casing In or, asin the embodiment shown in Figs. to 7, connected to the cylindrical wallI2 by lugs I6. The inner arms of the clips, which are encased withrubber bushings H, are secured to the motor casing by a metallic stripI8 encircling the latter.

The casing ID is formed of two wall mem.-..

bers, namely, a front wall member 20 and a rear wall member 2| heldtogether b'yia; number of screws or bolts 22. Since the fandrum I2 is ofcylindrical shape and the surrounding casing II) is essentiallybox-like. in character in the.

In the embodiments shown in Figs. 1 to 3 and Figs. 5 to '7 the damper orshutter is so constructed that theda'mper I I assumes a positionessentially parallel to the front wall m'ember-of the casing whenthe-damperisin'its closed and open positions.

ment which includes arms I and:-I26"joined together' byacross piecewl2'lpivotally connected to the damper by hinges'zd. Another" pair ofconnected arms-lzs is-pivotally mounted to the upper part of the outerwall member 20': by

hinges 26, the lower ends of theJar'ms-iI28being arranged toslideiagainst the-inner surface of the damper I I. and I26 are pivotallyconnected to the pairof arms I28'at thepointslZil. Arm md terminates atpoint I29 while: arm I25 continues downwardly and is connected to anactuating member" or lever 21; as best shown in--Figs-.-l' and 3:'1

In" the embodiment illustrateddn Figs: l to' 4,

the switch comprises a' controlcylinder'ifi; which is actuated step bystep to a: numberofdifferent positions by a pull-cord 29, aswill bedescribed presently; the cylinder with each downward pullon the cord 29:being moved"angularly--through-= 90 in the direction indicatedby: thearrows'in- Figs; 4, ea; lbanch 40.. In this manner the brushes 3|, 32and 33 will be successively inter--- connectedin pairs throughtheicontact segment 34. The sequence of operations on successive downwardpulls ion-the cord 29; as diagrammatically indicated in Figs. 4a; id andis that: the damper is 1 first: opened while the motor re- In thenextposition-seenin Fig. 4b the motor is started mains disconnected, as seenin Fig: la.

and runs at halfspeed. In the next position seen in Fig. 4c, the motorrunsat. full' speed. Finally, when the switch has againmeachedthestarting position illustratedin-Figi 4, the -motoris disconnected andthe damper is closed.-

The damper lI is actuated:by mechanism in cluding a cam element 35 whichis arrangedonr the fan motor i3,-either at halfor full speed,-is-

effected by a'tapSI arranged on thefield winding 36 of. the motor, asdiagrammatically-seenin:

Figs. 4, 4a,.4b and ic.

As seen in Figs; 1 to 3;.the damper II is supported byalazy-tongs'arranga' As :best seen in Fig; 3, therarmsi I25- As bestshown in Figs. 10, 11 and 12, the cam element 35 and lever 21 form partof a damper and switch operating mechanism including a cord wheel onwhich the cord 29 is anchored at 290. and wound thereon in such a mannerthat, when the latter is pulled downward, the wheel 60 is rotated 90 ina counter-clockwise direction from the position shown in Fig. 10. Suchcounter-clockwise turning movement of the cord wheelfit is .stoppedby.a..member .IiIv in the form of an. elongated '.:loop whichyis; pivotallymounted at one end at 62 to the cord wheel 50. The opposite end of themember BI is looped about a bolt or stud B3 and angularly movable about.Eth c flatter.

tends-from "such: stud and: is adapted to engage" one-of"thenotchesfifitoiretain :thewstep wheel 65 in its new position each time thelatteriszro tated90z While the 'step 'wheel. 6'5: is retainedzeach timethe position to which it is-irotated', .the r cord wheelfill-*returns'to the-dottedline-positionshown in Fig; lobytheraction'ofiaspring I8 when the I cord 29 is released: Theroam"discx35andrcontrol' cylinder" 28 F' of they switchare rigidly secured to thesame shaft 28a upon which thewsten-wheel S5 is mounted,- whileith-ecord. wheel fiil'z'iszireely rotatable on" such' shaft;

A cam rollerJI I is :rotatably' carriedioni an arm I2 which-is:pivotally. supported; onL thestud '68-.

The:lever21.- connected-tothe armzIZfw-of the? damper operatingmechanism; described above, is:operatively:,associatedrwiththearm,='d2.. Thev lever '21 is-formed from a==length of resilientrodhaving. a portion-21 wound about. the-hub of'the arm-12, and theleft-hand. endshownin v Fig.-- 10 is clamped: in :a hooked:portion-..'I3:of' the arm. 222' The arm I2; lever-211 and-:roller =-'I Iform anonseparable unit during-z-normalioperation of the controlmecha-"nis-m being:described;v In the event the=-dampenItI isaccidentally pushed to its closed position iwhenzthe. operatingmechanism is act ing .to i-maintainthe' damper open, thelever 2'3:yields due to its resiliency ,so i that: parts of: the

the-lever 21 imparts upward movement to' the arm- I 25. ofthe damperoperating mechanism to effect openingeof" the damper? I I. I When thecam disc-35sis subsequently moved to its dottedline positioninFig;10,-the rol1er- II is urged downwardly by the action of the damperclosing springaill: shown-id Fig. 3; Such downward movementoftherroller- 'II- can then-:take place inasmuch as the inwardly curvedportion of the camdisc 35 is then directed upwardly, as bestshownin.Fig.3.-- The advantage of-the regulating mechanismabovedescribed-is that only a draw. cord; chain orithe likeiis required toactuate the motor switch and: shutten oridamper- I I I In the embodimentshown in Figs. 5 to '7 and 13 to 19 the common actuating member for themotor switch and damper comprises mechanism including a plate 38 whichis reciprocably carried in an extension 39 which is fixed to the casingand serves as a guide. Movement of the plate 38 is effected exteriorlyof the casing by two cords 4| which pass over guide rolls 48 and areconnected to opposite ends of the plate, the cords passing throughopenings in the casing and freely hanging outside the latter. The plate38 is formed with a curved cam-groove 42 arranged to receive a lever210. which corresponds to the lever 21 in the embodiment of Figs. 1 to3, the lever 21a being connected to the arm H511 to guide the latter andimpart vertical movement thereto.

The plate 38 is also provided with a tongue 43 which is mounted in aninsulated manner thereon and adapted to cooperate with a switch, as willbe described presently. To hold the plate in a' number of differentoperating positions, it is formed with a number of openings 44 locatedaccording to such operating positions, the openings being adapted to beengaged by a ratchet spring 45 connected to the extension 39. As bestseen in Fig. 7, the switching provisions comprise two pairs of laminatedcontact springs 46 and 41 which are mounted on a contact member 48formed of insulating material and connected to the casing.

In operating the embodiment of Figs. 5, 6 and 7, a pull on the left-handcord 4| in Fig. 6 will move the plate 38 from the position shown inFigs. 6 and 7 to that shown in Figs. 13 and 14 to displace the lever 21upwards, so that the damper willbe opened. A further pull on the cordwill move the plate 38 from the position shown in Figs. 13 and 14 tothat shown in Figs. 15, 16 and 19' to cause the tongue 43 to bearagainst the pair of springs 46, with the result that the motor will bestarted up and be driven at full speed. Another pull on the'sameleft-hand cord 4| will move the plate 38 from the position shown inFigs. 15 and 16 to thats hown in Figs. 1'7 and 18 to cause the tongue 43to bear against the pair of springs 41, which efiects switching of themotor to half speed operation. When the right-hand cord 4| in Fig. 6 ispulled, themotor will again be switched to full speed operation and afurtherpull on the right-hand cord 'will disconnect the motor at whichtime the damper also will be closed.

In the control mechanism just described, it is possible to switch themotor any desired number of times between half and full speed operationsimply by pulling on either the right-hand or left-hand cord withoutactuating the damper operating mechanism. For the purpose of quicklyascertaining the operation of the ventilator unit, the reciprocableplate 38 is provided with an indicating device 49 which is visiblethrough an aperture 381 or window in the base of the casing, such device49 being in the form of a tongue which may indicate, as by its color,for example, whether the fan motor is disconnected or is being operatedat full speed orat half speed. An indicating device of a similar typemay also be provided in the embodiment illustrated in Figs. 1 to 3.

Figs. 8 and 9 show a modified damper construction in which the damper IIis inclined to the front side of the casing in its open position andparallel to such front side or face in its closed position. As best seenin Fig. 9, such damper operation is efiected by providing a torsionspring 58a between the arm |25a and the inside face of the damper, thespring being arranged so that it always will tend to maintain the damperin the inclined position indicated by full lines in Fig. 8. When thearms of the lazy tongs assume a folded position, the damper isautomatically moved to a position which is parallel to the casing, byreason of the fact that its upper edge, as indicated by dotted lines inFig. 8, will first be moved against the front wall of the casing.

If it is desired to cause the damper to be inclined to the vertical inits open position without employing the torsion spring 58a in the mannerjust described, an arrangement can be adopted which is shown in Fig. 8in which a chain 5| or the like is connected to the upper edge of thedamper and to the casing, the extent of the inclination being varied byadjusting the length of the chain. The provision of the chain 5| mayalso be of advantage even when the torsion spring 58a is employedbecause it tends to prevent rattling of the damper in its open position.In the embodiment shown in Figs. 1 to 3, the torsion springs arearranged to cause the damper II to bear resiliently against the arms I25and I26.

Although I haveillustrated and described particular embodiments of myinvention, I do not desire to be limited to the particular arrangementsset forth, and I intend in the following claims to cover allmodifications which do not depart from the spirit and scope of myinvention.

What is claimed is:

1. In a ventilating unit for circulating air through an existing airduct in a building wall of an enclosure having spaced apart inner andouter surfaces, such unit comprising a box-like casing including spacedapart first and second wall members constituting front and rear walls,respectively, each of the wall members being formed with an opening, anair passageway forming member extending between the first and secondwall members and terminating atthe openings therein, another memberwhich is spaced from the passageway forming member and connects thefirst and second wall members to form a substantially closed outerchamber exteriorly of the passageway, an electric motor, a fan carriedby the motor and driven by the latter, the fan and motor together takingup a'definite overall distance in the direction of the axes of suchparts, damper means for the'passageway, means for mounting the dampermeans on the casing for movement thereon between an open position and. ashut position at the first wall member or front wall of the'casing,electric switching means for controlling the motor, means for adjustingthe position of the damper means, the electric switching means anddamper adjusting means including parts'disposed in the closed outerchamber of the casing, means for mounting the casing on the buildingwall with the second wall member or rear Wall thereof at the innersurface of the building wall with the opening in such second wall membercommunicating with the duct, means for carrying the motor on the casingwith the fan disposed in the air passageway between the first and secondwall members and the motor projecting exteriorly of the casing from thesecond wall member or rear wall thereof so that the duct will constitutea housing for the motor when the easing is mounted at the inner surfaceof the building wall, the casing when mounted on the building wallprojecting from the inner surface thereof into the enclosure a distancewhich is less than the overall axial distance taken up by the fanandunotor, andtherdamperymeans: in itsp-shut' positionOlOSiIlQthGOPGDlIlEQlIl the firstwall member or::front wall of:the;casing,,

2.. The combination- :defined in claim :1 comprising; structureincl-uding 'the' electric switching means'xfor. operating-themotoratfullspeed or a reduced speed; the casing having a window, and

indicating means. in theouter closed chamber whiohis visible throughthewindow'to indicate the position of the switching-'m'eans'anddetermine whether-the:motordsstopped or-being operatediatifu'll or:reduced speed.

3:;The' combination-defined'inclaim l in which then'electricswitchingmeans includes a movable elementfor controllingsthe motor, and thedamperv adjusting means comprises mechanism includingrcam means and. a:cam-follower operable re sponsive-to'movementof the'element foradjustingzthedamper means, .the camzmeans constituting one of the: partsdisposediwithin the casing in thesclosed outer chamberiithereof.

4:;The combination defined'in claim 1 in which thesda'mper' meanszincludes ,:a vertically disposed plate movable. totand froma shutposition overlying theopening in the first wall member or front wall. ofthe casing and the means for mounting. the damper means on the casingincludes. spaced: apart vertically extending arms pivotally connected.at their upper-ends to the plater at' a region thereof which is locatedabove the .centerpf gravity of the, plate, said mounting means being soconstructed-and arranged that thearms' are essentially. parallel to thefirst wall member orfront wall of the casing when the damper means-isin"its shut position and the plate overliesthe-opening inthe first wallmember-andvthe armsare at an-acute-angle to the first wall member whenthe-damper means is-in,

itsopen position and theiplate is removed from theopening of.the-firstwall member, and the damper adjusting means includingstructureoperativelyconnected'to the arms for; moving the latter.

5. The combination defined in .claim 1 in which the electricswitchingmeans comprises a member which is movable back and forth inastraight line and-a switch unit having a movable partin the'pathofmovement of themember which is actuated by themember in one-positionthereof, mechanism operatively connectedto the damper means and to themember for. governing the posi. tion of theolamper meansaccordingtotheposition of themember in its straight lineof movement, and manuallyoperable means accessible exteriorly of the casing to impart movementback and forth inastraightline to the. member.

6..In a ventilator unit capable of circulating air through diiferentsize air ducts in building walls of enclosures having spaced apart innerand outer. surfaces,- such unit comprising a boxlike casing includingspaced apart first and sec ond wall members constituting front and. rearwalls, respectively, each of the wall members being formed with anopening, an air passageway forming member extending between the firstand second wall members and terminating at the openings therein, anothermember which is spaced from the passageway forming member andconnectsthe first and second wall members to form a housing exteriorly of thepassageway, an electric motor, a fan carried by the motor and driven bythe latter, the fan and motor together taking up av definite overalldistance in the direction of the axes of such parts, a shutter for thepassageway, means for mounting the shutter on I the casing for; movementlthereon: between trolling the motor, the control. mechanism includingarts disposedin the housing and a-man ually operable part accessibleexteriorly of; the.- casing, means for mounting the casing on a building wall having a duct with the second wall meme her or rear wallthereof at the inner'surfacerof the building wall with theopeninginsuchsec- 0nd wall member communicating' with therduct;

means for mounting-the motorron the casing with the fan disposed in the.air. passageway between the first and second wall members and the motorprojecting exteriorly of the casing from thesesond wall memberor.rea1"\.vall.ithereof so that'the duct will constitute; a housingfor themotor when the casing. is mounted: atgthe 'inner'surface' of thebuilding'wall; thecasing when mounted on the buildingwallprojecting'from: the inner surface thereof into: the-enclosure a.distance which is less than the overall axial distance taken up by thefan and'motor; the shutterinxits .shut position closing the. opening inthe first wall member or front wallaofi the casing,andl the means-formounting'thez motor being' so constructed and arranged that, when: the.second wall member or rear wall of'l'theecasing. overlies a duct, theventilator unit will be operablefiwhen the motor projects intmductsrof:different size, the maximum size ductiintoi. which: the motor canproject being dependenti'upon the size of the casing and theability'to..:position the; latter so that the rear wall thereof'overlies'the duct;

'7 A: ventilator unit. as set forth in claim 1 in which theelectricswitching means comprises a member which is movable back: and. forth ina straight line :and aswitchunit having 'a movable part in; the'path ofmovement of the member whichris actuaterlzby'the member in' one positionthereof, mechanism.operatively connected to the damper means: and tothemember for governing the positionrofi the damper means according to the"position. of the member in its-straight line ofunovement, and. manuallyoperable means in cluding pull cords: accessible exteriorly" of thecasing torimpart movement back and-forth in a straight line; to: the.member-,the member and mechanism. operatively.:connected thereto andswitch unit being.so=constructedvand arrangedthat, when movement isimparted to the member in one: direction: by one: of the pull cords, thedampermeans initia'llywill be opened and thereafter upon furthermovement'of the-rnember-to the one position the movable part of theswitch unit will bezactuatedto start the motor and'the damper means willremain open.

8. A ventilator unitasset'forth-in claim-1'7 in which the-electricswitching-means includes the first mentioned switch unit anda secondswitch unit also having a movablepart' inithe pathof movement of themember which is actuated by the member in another position thereof,. themember and. mechanism operatively. connected, thereto and. first. and.second switch'units being so constructed. and .arrangedthat, whenmovement isimparted to the member in'such one direction by theone pullcord; themotorwill .be operated'at one speed when-the movable'part ofthe first switch unit is. actuated by thememberand. operatedat adifferent speed. when the-movable part of the second switchis-thereafteractuated by the member and the damper means will be open at both motorspeeds.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Roth Aug. 15, 1922 Frank et a1 June 28, 1927 Van Zile June 3,1930 Morse Aug. 28, 1934 Ross Aug. 28, 1934 Ferris June 18, 1935 RossAug. 13, 1935 PI umber Name Date McLaughlin May 5, 1936 Melin Jan. 19,1937 Hueglin June 22, 1937 Morse Dec. 17, 1940 Benson Jan. 7, 1941Kidney June 2, 1942 Spear Apr. 13, 1943 Morrison Sept. 18, 1945 FOREIGNPATENTS Country Date Germany Apr. 21, 1933 France Jan. 9, 1937

